Vehicle transmission



July 14, 1931. A, B. GILBERT VEHICLE TRANSMISSION Filed' Feb. 2l. 1925 4 Sheets-Sheet l INVETOR. AZva Ga'Zert BY mi ATTORNEYS'.

July 14, 1931. A. B. GILBERTv 1,814,442

VEHICLE TRANSMISSION Filed Feb. 21. 1929 4 Sheets-Shet 2 @www f ATTORNEY5.

July 14, 1931. A. B. GLBERT VEHICLE TRANSMISSION Filed Feb. 2l. 1929 4 Sheets-Sheet 3 @was 1N VENTOR. AZva 5 Gert im MMX/ ATToRNEY 1929 4 Sheets-Sheet 4 A. B. GILBERT VEHICLE TRNsMssIoN Filed Feb. 21.

July 14, 1931.

1 JNVENToR. Alva-5f @bert BY' w@ 127cm/Em,-l

Patented July 14, 1931 Y l UNITED STATES PATENT oF'FlcwF.

Application tiled February 21, 1929. Serial No. 341,714.

This invention relates to improvements in views taken on the lines II-II and III- PIII vehicle transmissions, although in their of Fig. I; broader aspects some of the features of the Fig. IV is a horizontal sectional view takinvention are applica-ble to change speed en substantially on the line IV--IV of Fig. transmissions generally. The invention has I; Y

to do particularly with means fory enabling Fig. V is a detail view, partly in section, the operator to utilize atv will any one of illustrating the method I employ for impartan infinite number of speed ratios. ing movements of adjustment' to the hy- `One of the objects of the invention is draulic clutch valves; the provision of a transmission which will Fig. VI is a detail View of another portion 60 enable the operator to employ at any instant of the valve control mechanism; and the best possible speed ratio for the condi- Figs. VII, VIII, IX and X are 4transverse tion' confronting him at that particular insectional views taken substantially on the stant, instead of being limited, as in the lines VII-VII, VIII-VIII, IX-IX, and conventional transmission, to three different X-X of Fig. I.

speeds. If a power driven rotating element pos- Another object of the invention is to facilsessing considerable inertia, as for instance, itate and quicken speed changes in an aua fiy-wheel, is suddenly relieved of its load, tomobile and to reduce the noise incident to it accelerates rapidly.v If the load then be making Such Changes, returned, there is -a gain in torque repre- 70 rAnother object is to effect speed changes sented by the additional speed attained by without interrupting the application of dr1v` the said rotating element. The transmising force to the driven shaft, thus increas- Sion disclosed herein is an application of ing the efficiency of the transmission and this principle, involving the clutching and causing it to function smoothly during speed declutohing of the driving and driven shafts 75 changes, 1n `rapid succession so as to impart to the Another Object. is the elimination 0f the driven shaft a series of driving impulses. usual friction clutch, the use o'f which is es- In the embodiment disclosed, this clutching sentia-l'where the driven shaft must be disand deCllltChng Oecurs twice during each 3 connected from the driving shaft while a revolution Of the driving shaft. For a 80 speed change is being effected. given setting of the mechanism, the engine Another object is the provision of a Shaft turning at' a given speed produces a transmission which shall be adapted'to give series of impulses in the driven shaft which a flexible power application for driving a causethat shaft to turn with a lower s eed vehicle in which a relatively inflexible motor but With greater torque than it would ave 85 is employed, as for instance; a Diesel engine. were'it locked to the driving shaft. I also Still' another object is the provision of a -pI'OVide means for varying manually the hydraulic clutch of special design capable of leletlve lengths of the periods of clutching being set and released at rapidly recurring and declutching with this result that Vthe 40 intervals without, undue wenn greater the length of the clutching periods, 90

Other objects and features of novelty 'will the greater the speed of the driven shaft and appear as I proceed with the description of the lGSS the t0rque,`while the shorter the that embodiment of the invention which, for length 'of the clutching periods, the slower the purposes of the present application, I becomes the speed of the driven shaft and have illustrated in the accompanying drawthe'greater its torque. Carrying this con- 95 ings, in which: trol to its limits, I am enabled to stop the Fig. I is a longitudinal vertical section driven shaft by .reducingthe clutching pethrough a. vehicle transmission embodying riods to zero, and on the other hand I am r the invention; i I able to secure a direct drive from one shaft "o Figs; II 'and III are transverse sectional to the other by reducingthe declutching pe- 100 will now proceed with the description of the embodiment illustrated herein.

Referring to Fig. I, is a fragment of the crank case of an internal combustion engine, the rear main bearing of which is shown at 11. The crank shaft 12 at its rear end has a flange 13 upon which is mounted the engine fly-wheel 14. The latter has a cavity 15 in its rear side. The {ly-wheel 14 is secured to the flange 13 by means of a pair of bolts 16 having enlarged cylindrical heads 17 which serve as spindles for pinions 18. Arranged in alignment with the engine shaft 12 is a driven shaft ]9, upon the forward end of which is mounted a pinion 2O that extends between and meshes with both of the pinions 18.

The three pinions 18, 18, 20, together constitute a double gear/pump. The operation of the fly-wheel in the direction of the arrow, Fig. II, tends to cause the pinions 18' to roll upon the pinion 20 in the same direction and to produce a flow of oil or whatever liquid may be carried in the cavity 15.

On either side of the pinion 20, there are partition blocks 21 formed preferably as integral parts of the fly-wheel, these blocks having concave faces cooperating with the ends of the teeth on pinion 20. The opposite faces of the blocks 21 are also concave and are engaged by valve sleeves 22 which have a limited rotary movement, as will be presently explained.

The inner surfaces of the sleeves 22 are tapered, as illustrated in Fig. IV, for the reception of corres ndingly tapered oscillating plugs 23. ach plug is provided with a straight transverse slot or passage 24 and two curved slot-shaped passages 25, these passages being pairs of ports 26 and 27, respectively, in the sleeves 22.

The. forward end of shaft ..19 is rotatable in bushing 28 which fit into a bushing retainer 29 formed integral with a plate 30 that engages and is secured to the rear face of the fly-wheel. Rotatably mounted on the outer side of the retainer 29, there is a sleeve 31, which has a short radial flange at its forward end. A ring 32 overlaps the fiange on the forward end of the sleeve 31, and is held in that posit-ion by screws 33 which are set into the partition blocks 21 and extend through holes in plate 30. The sleeve 31 is thus held against longitudinal movement.

The flange at the forward end of the sleeve 31 is provided at diametrically opposite points with teeth 34, each of which engages a socket 35 formed in the rear end of one of the valve sleeves 22 (see Fig. V). Obviously, the rotation of sleeve 31 relative to the ily-wheel turns the sleeves 22 upon their axes, thereby varying the posiadapted to connect e tions of the ports 26 and 27. This relative rotation of the sleeve 21 is accomplished by means of a pair of spiral slots 36 in which run pins 37 that are mounted in sleeve 38. The pins 37 extend also through longitudinal slots 39 in the vbushing retainer 29. Hencethe sleeve 38 turns with the retainer 29 and, therefore, with the fly-wheel. The sleeve 38 is provided with a peripheral groove in which runs a collar 40 provided with outwardly extending ins 41, the outer ends of which are en aged y the bifurcated extremities of a roei lever 42. Hence the sleeve 38 with its pins 37 ma be caused to move backward and forwar and the engagement of the pins 37 in the spiral slots 36 transmits a turning movement to the sleeve 31 and through the teeth 34 and sockets 35 to the valve sleeves 22. The lever 42 may be connected by means of a link 43, adjustable as to len h, with a foot lever 44 that is adapted to swung through a limited angle by a foot pedal 45.

The fulcrum pin 46, to which the lever is attached, is mounted in suitable bearings in a casing section 47, the latter being preferably attached directly to the crank case 10 by screws 48 or the like. At its rear end, this casin section carries a vertical plate 49 to whic is attached by a series of screws 50 a gear housing 51. he screws 50 also extend through a ring 52 which engages a shoulder on a cylindrical element 53,V supporting the latter concentrically with respect to the shaft 19. The element 53 is provided with slots 54 through which the pins 41 extend.

At its forward extremity, the element 53 carries a cam 54 which, in the present instance, has two high spots. The cam is engagd by two followers 55, identical in form, ac of which has two engaging surfaces arranged 90o apart. The movements of the cam follower are very rapid, and hence the two follower surfaces are employed rather than a single surface held against the cam by spring pressure. The followers 55 are rigidly secured to fthe rear ends of the corresponding oscillating plugs 23, being centered by means Of-dowel pins 56 and fastened in place by screws 57. -The cam 54 is stationary, and the rotation of the flywheel causes the followers 55y to be rocked by the cam, and thus transmit oscillating motion to the plugs 23. The plugs 23 may be held to their tapered seats `1n the sleeves 22 by round ended screws 58 and lock nuts 59, these screws being threaded into a housing 60 which is secured to the rear face of the fly-wheel by screws 61. An oil-tight packing 62 seals the joint between the rotating housing 60 and the stationary cylindrical element 53.

The housing 60 at oppositely located mid portions is provided with integral cylinders 63 connected with the interior of the housing by oil holes 64. In each of these cylinders, thereis piston 65 kwhich 1s pressed forwardly by a coil s ring 66 against a stopl 67. The space in t e housing 60 at the 'th elongated hub portion of a pinion 71.

This pinion is fixed to the shaft 19,and hence the ball bearings`69 and 70 const1tute bearings for the shaft-.as well as for the pinion. 72 is a fixed shaft mounted in the late l49 and housing 51. Bearing rollers 3 surround the shaft 72 and rotatably lsupport a pinion 74 which meshes with the pinion 71.

The pinion 71 makes a substantially oil tight contact with the upper portion of the housing 51, as shown in Fig. VII, while the pinion 74 contacts through the greater portion of its periphery with an internal wall 75 in the housing.V Between the wall 75 and the lower part of the housing there is an oil passage 76. An oil inlet port 77 connects this passage with a copper tube oil line 78 leading from the delivery end of a pressure pump, (not shown). A flap valve 9 is arranged to seat upon the metal around one end of the passage 76, being hinged at 80 in a bracket 81 secured' to thecasing 51 by screws 82. A coil spring 83 working against the spherical head of a pin 84, presses the valve 79 toward its seat.

Secured upon therear end of shaft 19` is a hub 85 which is recessed at intervals throughout itsperiphery for the reception of anchoringl pins 86, by means of which one or more helical springs 87 are secured to the shaft. In the embodiment illustrated, I employ three such springs. Their outer extremities are anchored upon pins 88 which are carried by the two parts, 89 and 90 of a spring housing, these parts being held together by screws' 91 or other suitable means.

Intermediate the pins 86, the hub 85` is provided with sockets 92 in which are seated coil springs 93 that press against the forward element of a multiple .plate clutch 94. The driving elements of thisclutch are provided with projections 95 that work in wide spline grooves 96 formed in the hub 85, whereby some little relative movement is possible between the driving plates and the shaft 19. The -driven plates of this clutch are provided with projections 97 which fit corresponding grooves in an extension of the housing member 89. The plate element which is furthest away from the coil springs 93 abuts against a collar 98 that is a further extension of the housing 89, and is rotatably supported at its rear end upon a roller bearing 99.

In alignment with the driven shaft 19, andto the rear thereof, is a further shaft 100, hereinafter referred to as the propeller shaft, although as shown herein the shaft 100 in reality constitutes only the forward portion of the propeller shaft, the rear portion of which would normallybe attached to the shaft 100 by a universal joint. The shaft 100 is mounted in a pair of ball bearings 101 and 102 which are carried by bearing supports formed integral with a casing section'103 that is attached to the section 47 by screws 104 or the like. In an axial bore in the frontend of shaft 100 I mount to slide a cylindrical slide bar 105 having a tapered front end. Near its rear end, the bar 105 carries a transverse pin 106 which is mounted in a ring 107 forming one side of a groove for a collar 108 that is connected in the usual" manner with a bifurcated lever '109 secured to a rock shaft 110 which may be manually oscillated by any desired means. Slots 111 in the shaft 100 permit the pin 106 to move back and forth.

Between the bearings 99 and 102, the shaft 100 has a flange 112 to which a drum 113 is riveted. On a forward extension of the drum 113, I rovide an internal' gear 114. lVithin the drum 113 there is a pair of shoes 115 adapted to bear frictionally upon the drum. The shoes 115 are connected by means of tongue and groove joints 116 with brackets 117 secured to the collar 98. The ends of each pair of shoes 115arej'connected by toggle links118 to a fitting 119 which surrounds a. pin 120 havin a large head with a curved end face bearing upon the slide bar 105. The pin 120 may be adjusted in the fitting 119 by means of a nut 121 threaded upon the pin and adapted to pull against a coil spring 122, which bears at its respective ends against the headof the pinfand against the end of fitting 119. A second coil spring 123, surrounding the spring 122, bears at one end against the head of pin 120 and at the other end against an abutment plate 124v screwed to the collar 98. When the parts are in the position illustrated in Figs. I and X, the heads of pins 120 are in enga ement with the cylindrical surface of slide ar 105. At such times, the pins `120 are forced outwardly against the pressure ofcoil springs 123, and the toggle links 118 are operated to force shoes 115 into which it is attached to the extension of the casing section 89, that is the integral portion between that section and the collar 98. Mounted on this same extension, s0 as to be capable of rotation relative thereto, 'is a ring 127 which carries a drum 128 that surrounds but does not touch the gear 114. This drum may be held against rotation by a band 129 lined with friction material 130. The band 129 carries end pieces 131 having bifurcations through which extends a shaft or rod 132. The latter is provided outside the end pieces 131 with stop collars 133 and 134. The collar 134 has a cam face cooperating with a rotatable cam 135, whereby the band may be contracted to grip the drum 128. A coil spring 132 surrounding the rod 132 tends to return the parts to the position illustrated in Fig. IX. The ring 127 has bolted or riveted thereto at intervals U brackets 136 which extend over the ends ot' spindles 137 formed upon the rings 127., These spindles carry pinions 138 which mesh with the ring gear 125 and with the internal ring gear 114. When the ring 127 is held still by the band 129, 130, rotation is transmitted from ring gear 125 through pinions 138 to internal gear 114 in a reverse direction and at a lower speed. Obviously, however, the direct drive .clutch 113, 115 must first be released before the reverse drive can be employed. To this end, the rock shaft 11G Vand the cam 135 may be so connected as to be operable either by a single control means or by two separate control means, the single means being preferred.

An oil pan 139 may be supplied to extend underneath both ofV the casing sections 47 and 103 and even underneath the engine. The oil delivered through pipe 7 8 may come from the pressure pump employed to force oil to the various bearings of the engine,

or from a separate pump as desired. An oil port 140 connects the space within the housing 51 with the space within the cylindrical element 53, from which it has free access to the space within the housing 60. From there it flows through suitable openings 140 in the plate 30 into the pockets 150 of the fiy-wheel. Passages 141 connect the pockets 150 with a cavity 142 in the forward side of the fly-wheel at the center thereof. Oil may pass from this latter cavity through an adjustable pressure relief valve located in the rear end of the crank shaft 12. This relief valve comprisesa ball 143 held to its seat by a spring 144, the tension of which is adjustable by means of athreaded hollow plug 145. The ball and spring 143, 144 are located in a socket 146 in the crank shaft, from which passages 147 extend radially to the periphery of the shaft.

Operation-Assuming that the transmission is employed in an automobile, and that the engine thereof is in operation, and assuming that the valve sleeves 22 are in the neutral position, that is the position illustrated in Fig. Il, the plugs 23 are then oscillating, being operated continuously from the crank shaft 12 through the fly-wheel 14 and the followers 55 running upon the fixed cam 54. The oscillations of the plug 23 are through a limited angle however, which is insufiicient to move the passages 24, 25 entirely out of register with the ports 26, 27 when the latter are in the position illustrated. The rotation of the fly-wheel in the direction indicated by the arrow in Fig. II rolls the pinions 18 around upon the then stationary pinion 20. The resulting rotation of the pinions 18 upon their own axes carries oil from the pockets 150 into pockets 151, tending to fill the latter completely and to leave the pockets 150 more or less unfilled. This does not actually occur, however, as the oil is free to flow through the ports 26, 27 and passages 24, 25. Hence, the rotation of the pinions 18 results merely in a flow of oil in an endless path in the cavity 15, with no force of any moment exerted upon the pinion 20. While this is going on, oil is flowing from the oil ump, not

`shown, through the tube 78, port 7 assage 76, and port 140 into the spaces wlt in the cylindrical element 53 and housing 60, through passages 140 in plate 30 into pockets 150, through passages 141 into cavity 142, and thence through the relief valve, pocket 146 and passages 147 back to the crank case. This circulation not only serves to keep the` oil pressure in the mechanism up to al predetermined value controlled by the setting of the hollow plug 145, but also prevents the oil within the cavity 15 and within the housing 51 from getting too hot. N ow, in order to ut the automobile in motion in a forwar direction, the driver laces his foot upon the edal 45 and rocks 1t slowly in the anti-Cloe wise direction, as viewed 1n Fig. I. The pins 41 are thereb moved rearwardly, carrying along wit them the sleeve 38 to which the pins 37 are attached. These latter pins, moved in the Strai ht slots 39 of the bushing retainer 29, are t ereby prevented from revolving independently of the iy-wheel. Their movement along the spiral slots 36 of the sleeve 31 rotates that sleeve. Its rotation is transmitted through teeth 34 and sockets 35 to the valve sleeves 22, thereby moving the ports 26, 27 to one side of the posltions illustrated, with the result that for a very brief interval during each oscillation of the plugs 23, the passages 24, 25 are closed. During such intervals, the pockets 151 become completely filled, and as oil is noncompressible and no more can enter these pockets. the rotation of the pinions 18 is niomentarily stopped. In other words, the pinions 18 are locked to the pinion 20. A

of the plugs 23, wit

. rotational impulse is thereby delivered/ to the pinion 2Q and tothe shaft 19 of which it is a part. v

If the pedal 45 be rested at this position, [these power impulses will beV delivered to the pinion and shaft 19 at regularly recurring intervals, that is twice during each revolution of the crank shaft; The strength of each impulse will depend upon the length of time lbetween impulses, as it is during such time A,that momentum is built up in the fly-wheel. In the case now assumed, Vthe momentum of the fly-wheel for the Vgiven engine speed, will be substantially at its maximum and thi/eJ torque impulses delivered to the shaft 19 will be at their maximum. But inasmuch asthese torque impulses are separated by relatively long periods, the speed minimum. A very heavy torque at extremely low speed may thus be utilized.

Now, assuming that the driver continues the tilting of the pedal 45 in the same direction gradually as the automobile gains momentum, the valve sleeves 22 -will turn slowly, thereby graduall increasin the time in each revolution 1ring' `whic 'the passages 24, 25 are completely cut off, and thereby increasing the length of time during which the power impulses act, while decreasing the length of time between impulses. The torque delivered to the shaft 19 will thus gradually decrease and the speed of rotation of that shaft will gradually increase. Throu hout this operation, driving force is being elivered to the shaft 19 durmg each revolution instead of being removed entirely for an interval, as it must be in the o ration of the conventional change s ee (gearing. Furthermore, the torque de ivere may be made to approximate the ideal value for each instant of operation.v Consequently, the length of time required to accelerate an automobile from standing start to high speed is much reduced over that required by the conventional transmission. f

When the pedal. 4'5 has been rocked to 1| the limit 'of its motion, the sleeves 22 will have been rotatdsuci'ently to out oft` the e324, 25 durin the entire oscillation the result that the pinions 18 and 20I are locked together, and theV drive is direct and entirely continuous, that is 'without any power impulses. The reduction of speed and the removal of the drivin power fromthe shaft 19 is accomplishe by the tilting of the pedal in the reverse direction with the consequent manipulation of the valve sleeves 22 in the reverse direction, as will be readily understood. When the ports 26, 27 are in their fully open position, corresponding to neutral in the conventional transmission, no

of rotation of the shaft 19 will be at a" pdwerimpulses are transmitted to the shaft 19 4to be somewhat harmful to the driving mechanism, I interpose between the shaft 19 and the propeller shaft a cushioning means to absorb portions of these impulses j and redeliver them to the shaft 100, thereby 75 smoothing out the driving force. This cushioning means may take various forms, but that illustrated in the drawings will answer the purpose satisfactorily. The power impulses are transmitted by the shaft 19 to the inner ends of the springs 87, winding up these springs to a greater or lesserV extent. The power thus stored in the springs is then more gradually delivered to the shaft '100 through the housing 89 and collar 98, clutch 115, 113 and flan e 112. At times when the load is removed rom the shaft 100, as when'v the clutch 115, 113 is released preparatory to using reverse ear, or when the rear wheels of the automo ile arel bouncingover roug'h 1 places in the road, the springs 87 might un'- wind too ra idly. To offset this condition, I have supp ied the multiple plate clutch 94 which merely introduces friction to slow up the unwinding movement above referred to.

An overrunning clutch m-ust also be applied to the shaft 19 in order to prevent the unwinding force of the springs 87 from being applied to that shaft instead of to the shaft 100. While it is appreciated that urely mechanical overrunnlng clutches mig t be utilized in this connection, I prefer to em' ploy the hydraulic clutch illustrated in F ig. VII. It is believed to be quicker in operation than a purely mechanlcal clutch. The pinion 71 rotates in the direction indicated y the arrow in Fig. VII. Oil is thereby taken from the space 152 and carried up and around into the passage 76. The pinion 7 4, of course, moves in the opposite direction, carrying oil downwardly and around into the passage 76. Vhen this occurs, the flap valve 79 opens and oil enters the space 152 from the passage 76. The unwinding of the springs 87 tends to produce rotation of the pinion 71 in the direction reverse to that indicated by the arrow in Fig. VII. Such rotation would put pressure upon the oil in space 152, seating the flap valve 7 9 and holding it seated. There being thenno exit for oil pumped into the space 152, the pumping must cease, which means that the pinions 71 q and 74 cannot 4rotate in the reverse direction.

In the ordinary forward traveling of'the automobile, the clutch 113, remains constantly set. It is released only at times when the driver desires to utilize his reverse gears. At such times, the pedal 45 will be set in neutral position. The clutch 113, 115 will then be released, and thereafter the cam 135 will be operated to cause the bandj 129,130 toy use, in this connection, of any means, includ-l ing purely mechanical mechanisms, for accomplishing the results stated.- I have shown two oscillating plugs 23, as the balance of the ily-wheel is better maintained in this manner, than it could be where onl one such plug is employed, but it should understood that the number of these plugs may be varied as desired. The number of oscillations imparted to each plug may also be varied so as to produce one or more impulses per engine revolution. When the main clutch is disenga ed the reactionary force ofthe propeller sia t torque is transmitted to the'case by the over-running clutch. The latter is relieved of this force at the instants when the main clutch is in engagement.

v This intermittentapplication of forceV to,

and removing it from, the casing'causes vibrations.

I repose to take advantage of this fact for e purpose of causing the vibrations due to these'impulses and the vibrations due to tor ue impulses in the engine to counteract eac other more or less. In order to do this, it is necessary to impart the correct number of impulses to the driven shaft for each revolution of the engine, that is to'say, two such impulses where a four cylinder, four cycle engine is used, three s uch impulses for a six cylinder, four cycle engine, four for an eight cylinder, four cycle engine, etc. The

i proper timing of the impulses with respect to the torque vibrations can best be determined by trial.

Numerous other changesnot specifically mentioned may be made without departing from the spirit of the invention, and I desire it to be understood that such detailed disclosure as has been made herein is primarily for the pur ose of fully illustrating the invention, an is not to be construed as a limitation upon the scope thereof.

Having thus described my invention, what I claim is:

1. In mechanism of the class described, a drive member, a driven member, 4a clutch adapted to hold said members against rotationl at different speeds, and means independent of the relative speeds of rotation setting of said members for automaticallr and releasing said clutch periodica 2. In mechanism of the class described, a power shaft, va driven shaft, a clutch adapted to hold' said shafts against relative rotation, and means unaffected by the relative speeds of the shafts and actuated automatically from one of the said shafts only for setting said clutch during a portion only of each revolution of that shaft.

3. In mechanism ofthe class described, a power shaft having a fly-wheel, a d riven shaft invalignment with said power shaft,

a clutch carried partially by said fly-wheel and partially by said driven sha and means independent of the relative speeds of rotation of saidshafts and actuated fiom one of said clutch carrying elements only for automatically setting and releasing said clutch periodically.

4. In mechanism of the class described, a power shaft, a driven shaft, a hydraulic clutch adapted to hold said shafts against relative rotation, and means actuated from one of said shafts only for setting and releasing said clutch periodically.

5. In mechanism of the class described, a

power shaft, a fly-wheel associated therewith, a driven shaft in alignment with the axis of said fl -wlieel, said fly-wheel having therein an en less passage, a barrier extending across said passage, said barrier comprising a fluid `vpump carried partially by said iy-wheel and partially by said driven shaft, the relative movement of said parts of said pump permitting rotation of the flywheel with respect to the driven shaft, and means timed to the rotation of said flywheel acting periodically to permit flow of fluid from one side of said barrier to the other.

6. In mechanism of the-class described, a power shaft, a driven shaft, a clutch adapted to hold said shafts against relative rotation, and means independent of the relative speeds of rotation of said shafts, and actuated automatically from said driving shaft only for setting and releasing said clutch periodically.

7. In mechanism of the class described, a power shaft, a driven shaft, a clutch adapted tohold said shafts against relative rotation, means actuated from one of'said shafts for setting and releasing said clutch periodically, and manually operable means for varying the relative lengths of tlie set and 'released periods.

8. In mechanism of the class described, a power shaft, a driven shaft, a clutch adapted to hold said shafts against relative rotation, means actuated froin'one of said shafts for setting and releasing said clutch periodically,and means for varying the relative lengths of the set and released periods.

9. In mechanism of the class described, a power shaft, a driven shaft, a clutch adapted to hold 'said shafts against 'relative rotation,

` means automatically operative during a fraction of each revolution for maintaining said clutch in set position, and manually operative means for varying the value of said fraction.

11. In mechanism of the class described, a

Vpower sha-ft, a driven shaft, a clutch adapted to hold said shafts against relative rotation, means automatically operative during a fraction of eachrevolution for maintaining said clutch in set position, and means for varying the value of said fraction.

12. In mechanism of the class described, a power shaft, a driven shaft, means interposed between said shafts for clutching and declutching them periodically, and means for varying the periods of clutching from zero through a plurality of increasing values up to one hundred per cent substantially.

13. In mechanism of the class described, a power shaft,A a driven shaft, means interposed between said shafts for clutching and declutching them periodically, and means i operable during the rotation of said driven shaft for varyingr the periods of clutching from zero through a plurality o f increasing values up to substantially continuous clutching, the periods of declutching varying proportionately in the inverse iat-io down to zero.

14. In mechanism of the class described, a power shaft, a driven shaft in alignment therewith, a clutch adapted to holdv said shafts against relative rotation, means actuated from one of said shafts for setting and releasing said clutch periodically, and means manually operable during the rotation of said driven shaft for varying the relative lengths of said set and released periods.

15. In mechanism of the class described, a power shaft, a driven shaft in alignment therewith, a clutch adapted to hold said shafts against relative rotation, means actuated from one of said shafts for setting and releasing' said clutch periodically, and means op'erable'during the rotation of said driven shaft vfor varying the relative lengths of said set and released periods.

16. In mechanism of theclass described, a power shaft, a driven shaft, a hydraulic clutch adapted to hold said shafts againstr relative rotation, means actuated from one of said shafts for setting and releasing said clutch periodically, and a manually con- Ltrolled valve in said hydraulic clutch for varyino' the relative lengths of the set and released periods.V

17. In mechanism ofthe class described, a power shaft, a driven shaft a hydraulic clutch adapted to hold said shafts against relative rotation, means actuated from one of said shafts for setting and releasing said clutch periodically, and a valve in said hydraulic clutch operable for varying the rel ative lengths of the set and released periods.

18. In mechanism of the class described, a power shaft, a driven shaft, a hydraulic clutch adapted to hold said shafts against relative rotation, said clutch comprising liquid filling an endless path of flow, a pump having relatively movable parts carried by said two shafts, the rotation of the driving shaft with respect to the driven shaft operating said pump to produce such flow, and means for periodically interfering with the flow of the liquid, whereby the pump locks the said shafts together intermittently to deliver energy built upin the power shaft during the pumping interval.

19. In mechanism of the class described, a power shaft, a driven shaft, a hydraulicV clutch adapted to hold said shafts against relative rotation, said clutch comprising liquid filling an endless path of fiow, a pump having relatively movable parts carried by said two shafts, the rotation of the driving shaft with respect to the driven shaft operating said pum-p to produce such flow, means for periodically interfering with the flow of the li uid, whereby the pump locks the said shats together intermittently to deliver energy built up in the power shaft during the pumping interval, and means for manually controlling the relative lengths of said periods of interference. v

20. Inmechanisni of the class described, a power shaft, a driven shaft, a hydraulic clutch adapted to hold said shafts against l relative rotation, said clutch comprising liquid filling an endless path of flow, a pump having relatively movable parts carried by said two shafts, the rotation of the driving shaft with respect to the driven shaft Operating said pump to produce such flow, means for periodically interfering with the flow of the liquid, whereby the pump locks the said shafts together intermittently to deliver energy built up in the power shaft during the pumping interval, and means fof controlling the relative lengths of said periods of interference.

2l. In mechanism of the class described, a power shaft, a driven shaft, a hydraulic clutch adapted to hold said shafts against relative rotation, said' clutch comprising liquid'filling an endless path of flow, a pump having relatively movable parts carried by said two shafts, the rotation of the driving shaft with respect to the driven y yduring the rotation of said driven shaft for shaft operating said pump to produce such fiow, means for periodically interfering with the flow of the liquid, wherebythe pump locks the said shafts together intermittently to deliver energy built up in the power shaft during the pumping interval, and resilient means for relieving the fluid pressure on said pump.

22. In mechanism of the class described, a power shaft, a driven shaft, means interposed between said shafts for transmitting motion in impulses from one to the other at different average speeds, and means manually operable during the rotation of said driven shaft for varying the speed ratio between said shafts. l

In mechanism of the class described, a power shaft, a driven shaft, means interposed between said shafts for transmitting motion in impulses from one to the other atl different average speeds, and means operable terposed between said fly-wheel and driven" shaft for transmitting a number'of power impulses to said shaft during each revolution of the fly-wheel equal in number to onehalf the number of said cylinders.

26. In mechanism of the class described,

' driving and driven shafts, a hydraulic clutch interposed between said shafts adapt-- ed to lock them together against relative rotation, and means for circulating liquid through said clutch to prevent excessive heat therein.

27. In mechanism of the class described, a power shaft, a driven shaft, a hydraulic clutch adapted to hold said shafts against relative rotation, said clutch comprising liquid filling an endless path of flow, a pump having relatively movable parts carried by said two shafts, the rotation of the driving shaft with respect to the driven shaft operating said pump to produce such flow, means for periodically interfering with the flow of the liquid comprisingpa ported valve member arranged to be oscillated by the rotationof the power shaft, whereby the pump locks the said shafts together intermittently to deliver energy built up in the power shaft during the pumping interval, a second ported valve member arranged to cooperate with said first member, and means movable axially of one of said shafts for varying the position of said second member, whereby the periods of interference may be lengthened or shortened.

28. In mechanism of the class described, a power shaft, a driven shaft, and means interposed between said shafts for transmitting a power impulse to the driven shaft during a fraction of each revolution of the power shaft without regard to the relative speeds of the shafts, the duration of the individual impulses bein variable.

29. In mechanism o the class described, a power shaft, a driven shaft, and means interposed between said shafts for transmitting a power impulse to the driven shaft during a fraction of each revolution of the power shaft without regard to the relative speeds of the shafts, the intensity of the individual impulses increasing with the length of the interval between impulses, and the duration of the individual impulses being variable.

30. In mechanism of the class described, a. power shaft, a driven shaft, and means interposed between said shafts for trans mitting a power impulse to the driven shaft during a fraction of each revolution of the power shaft without regard to the relativel speeds of the shafts, the intensity of the individual impulses being variable.

In testimony whereof, I hereunto aix my signature. ALVA B. GILBERT. 

